Styles Screwed Up After My Last CVS Update

I havent done a CVS update in a while, but i did one last week and now styles are acting screwy. If i use a given layout with two user accounts, and one changes the theme, all others using the same layout are changed to that theme. If the user who didnt make the change then tries to add or change customizations, they get an error stating "Style not found". Any idea what going on here?